From local qualities to global morphology: The typology of road nodes and its effect on the morphology of the traditional urban fabric

Abstract

Urban morphology has been the center of interest of numerous studies for several decades. The objectives of these studies vary from the simple understanding of the urban form to more elaborate endeavors aiming to create an analytical model that can be tested against sociological, economic, and/or demographic aspects of urban settlements. Some recent approaches integrate the analysis of urban morphology into the generative design process. Yet, a simple comprehensive analytical model that can be exploited readily in an urban generative methodology is missing. This paper presents part of a suggested method for analyzing the traditional (organic) urban fabric within a study aiming to arrive at a simplified generic model of the traditional urban form. That aimed generic model would be a starting point in a generative design process that simulates the morphological characteristics of the urban tissue under study. The hypothesis behind this work is that the study of local morphological factors – the typology of road nodes – can lead to an understanding of the global morphology of the urban tissue. The proposed analytical method includes two main axes. The first is to study the typology of road nodes within the traditional fabric. The second axis concerns how these nodes relate to each other to form the urban fabric. This paper focuses on the first axis related to the study of the typology of road nodes within the urban fabric. The typological classification of nodes in the urban fabric is simply based on the number of connected roads and the continuity or discontinuity of these roads through the node. The question of continuity is treated using the (Visual Step) concept. Coupled with a global analysis of the relation among the nodes, and based on the idea of (Urban Layering), a simple but informative generic model for the morphology of the urban tissue can be generated. The selected context for the case study is the Old City of Mosul in Iraq, which is now listed on the tentative list of the UNESCO world heritage sites.